Currently, with F1's existing V8 formula facing its final season in 2013, there are four engine suppliers on the grid -- Ferrari, Mercedes, Renault and Cosworth, the British independent.

But the rules are changing radically, as from 2014 cars and drivers must be powered by turbo V6s complemented by sophisticated KERS systems.

Late in 2011, there were rumblings Cosworth - left with just two customers this year in the form of struggling Marussia and HRT - might not be able to commit to expensive V6 research and development.

Indeed, even the viability of Cosworth staying around for the final V8 season has been the subject of recent paddock speculation.

"Cosworth, for sure, are finished," Renault's Jean-Francois Caubet is quoted now by German-language website motorsport-total.com.

And Craig Pollock, whose new PURE foray is developing a V6 for 2014, agreed: "Cosworth cannot be there in 2014.

"They just can't make it in time now, no matter what anybody says," he told the Dutch website gpupdate.net. "It's an absolute impossibility."

Recently, Cosworth lost its best customers - Williams and Caterham - to Renault, as the French supplier pushes harder for the FIA to further relax the rules about how many partners each carmaker can supply.

"I am pushing for an open market because we are in Formula One and regulations cannot solve all the problems," Caubet was quoted as saying last year.